Apparatus for the edge-to-edge glueing of veneers

ABSTRACT

A METHOD FOR THE EDGE-TO-EDGE GLUEING OF VENEERS, WHEREIN A POWDERED GLUE OR ADHESIVE IS INTRODUCED IN A MEASURED DOSE INTO A GAP BETWEEN ADJACENT VENEERS AND THEN THE POWERED GLUE OR ADHESIVE IS HEATED UNTIL IT SETS WHILST THE VENEER EDGES ARE PRESSED TOGETHER.

Jan. 26, 1971 a. ORTEL APPARAiUS FOR THE EDGE-TO-EDGE GLUEING OF VENEERS Filed Aug. 14,1968

2 Sheets-Sheet X 3 N t n 3 mm mm NM 2. mm mm mm mm RQM A In van/0r Jane 01971 G. ORTEL 3,558,39

APPARATUS FOR THE EDGEhTO-EDGE'GLUEING ORVENEERS Filed Aug. 14, 1968 2 Sheets-Sheet 2 In van or Gamma 0/?7'51.

United States Patent -Gerhard Ortel, Rietberg, Germany, assignor to Firma Heinrich Kuper, Westphalia, Germany Filed Aug. 14, 1968, Ser. No. 752,624

Int. Cl. B29c 19/00 i Claims ABSTRACT OF THE DISCLOSURE A method for the edge-to-edge glueing ofveneers, wherein a powdered glue oradhesive is introduced in a measured dose into a gap between adjacent veneers and then the powered glue or adhesive is heated until it sets whilst the veneer edges are pressed together.

A This invention concerns a method and an apparatus for the edge-to-edge glueing of veneers or the like.

In conventional apparatus for the edge-to-edge glueing of veneers, the veneers are conveyed in the direction -of the fibre (longitudinal direction) and are wetted with glue or the like along the abutting edges during their travel, thus achieving a glued butt joint.

Such devices operate with synthetic glues which are mixed with water and rapidly bond under heat andpressure. However, this has the disadvantage that these glues 'can'remain in the pot for only a limited time and there- 'fore repeated cleaning .of the containers and the coating factory in operation;

Ari object of the present invention is to provide, whilst avoiding the previous disadvantages, a-method of edgeto-edge glueing of veneers by which a perfect glued joint is obtained, and an apparatus for carrying out the me od which is both practical and economical on account of its simple construction and satisfactory operation.

According to the present invention, in 4 method of edge-to-edge glueing of veneers, a portion of powdered glue or adhesive is introduced into the joint of adjacent veneers'and thenthe powdered glue dr'adhesive is heated until it sets whilst the veneers are pressed together.

' An: apparatus for the edge-to-edgeglueing of veneers,

1 more particularly for carrying out the method, is characterised by a device which proportions and feedthe .powdered glue or adhesive in a loose condition and is associated with a conveyor pressing the veneers together, a heating device being provided in the region of the joint. In a preferred embodiment the proportioning device may i be provided'with a feeding disc rotating perpendicularly to'theplane of movement of the veneers in the region of the joint and having grooves uniformly distributed over its periphery for carrying the powdered glue or adhesive.

The heating device is arranged behind the proportioning device and'may be provided above and below the plane of movement oft he veneers.

In another feature of the invention, the conveyor may be formed by a belt provided below the plane of movement of the veneers and by several compression rollers above said plane moving in the direction of the veneers and joining them together tightly, said rollers being connected together in the manner of a roller chain and ca- 3,558,398 Patented Jan. 26, 1971 pable of being arranged to rotate loosely round the upper heating device.

The conveyor may be formed of plate discs arranged below the plane of movement of the veneers, pressing said veneers together tightly against pressure rollers provided above the plane of the veneer.

The apparatus according to the present invention makes it possible to carry out a method for the edge-to-edge glueing of veneers, by which the best possible glued joint is obtained. The apparatus is characterised by great simplicity, reliable operation and ease of use. The preferred construction of the apparatus ensures a high speed of movement and a neat and efiicient butt-jointed connection of the veneers.

Embodiments of the invention are illustrated in the accompanying drawings in which:

FIG. 1 is a side view of an apparatus for the edge-to edge glueing of veneers, comprising a proportioning device and a conveyor associated therewith, consisting of a lower conveyor belt and upper press rollers, and also a heating device provided in the region of the conveyor, shown schematically,

FIG. 2 is a plan view of a part of the same apparatus.

FIG. 3 is a plan view of several pressure rollers of the conveyor, arranged in series in the manner of a roller chain,

FIG. 4 is a side view of an apparatus for the edge-toedge glueing of veneers in a modified embodiment, with a heating device associated with a proportioning device and a conveyor formed of lower plate discs and upper pressure rollers shown schematically, and

FIG. 5 is a plan view of the same apparatus.

In IG. 1, an apparatus for the edge-to-edge glueing of veneers comprises a plane work table 10 as a surface for supporting the veneers 11 to be glued. In the front centre; area of the 'work table 10 (viewed in the direction 'of movement of the veneers 11) there is a thin stop ledge 12 which .keeps the veneers 11 to be glued with a certain jointing space between them, so that the adjacent veneers 11 are conveyed with this jointing space between them to a proportioning or dosing device 13. The proportioning device 13 dispenses a measured dose of pow dered glue or adhesive into the gap 14 between the adjacent veneers 11; the proportioning device 13 is contained in a divided housing 15 in which a feeding disc 17 rotating in the region of the joint between the veneers 11 perpendicularly to their plane of travel and in the direction of movement thereof, is provided to rotate in a storage chamber 16. The feeding disc 17 has receiving grooves 18 arranged uniformly over its periphery and having a semicircular or angular cross section, said disc preferably corresponding in its thickness to the width of the joint.

In the upper region of the housing the storage chamber 16 is provided with a filling aperture 19 and in the lower region of said housing the storage chamber 16 has an outlet slot 20. The feeding disc 17 is in sliding contact with the wall of the storage chamber 16 by its rotating surface, whereby the receiving grooves 18 form conveyor chambers closed in the area of movement between the filling opening 19 and the outlet slots 20. A hopper 22 mounted in the upper region of the housing and receiving the powdered glue or adhesive 21 is arranged at the filling aperture 19, from which hopper 22 the powdered glue or adhesive 21 drops into the receiving grooves 18 of the feedings disc 17. In order to keep the powdered glue or adhesive 21 in a constantly loose condition, the hopper is provided with a loosening device 23 comprising a disc 25 fitted with pins 24. The pins have a smaller cross section than the receiving grooves 18 of the feeding disc 17 and engage loosely in the reciving grooves 18; during the rotation of the feeding disc 17 the loosening device 23 is set in a rotary motion by its pins 24 engaging in the receiving grooves, whereby the powdered glue or adhesive 21 in the hopper 22 is always circulated and is thus kept in a loose condition. The outlet slot 20 corresponds in width approximately to the width of the feeding disc 17 and thus to the width of the receiving grooves, but in its length is formed to correspond at least to the length of the receiving grooves, but is preferably greater than the length of said receiving grooves 18.

Below the proportioning device 13 a conveyor belt 28 is mounted on the work table and rotates endlessly about two conveyor discs 28, 27. The conveyor belt is formed as a steel band and its width is a multiple of the joint width. This conveyor belt 28 (see FIG. 1) has, in the region of its two longitudinal edges, recesses 29 spaced one behind the other in which pins 30 of the driving conveyor disc 26 engage and thus drive the conveyor belt 28. Raised side edges 31 of the conveyor discs 26, 27 ensure reliable guidance of the conveyor belt 28.

The upper length of the conveyor belt 28 passes over a heating device 32 which is arranged between the two conveyor discs 26, 27 and extends from the conveyor discs 26 in the longitudinal direction of the joint as far as the proportioning device 13, but is spaced from the outlet slot (see FIG. 1). This lower heating device 32 transmits its radiated heat to the upper length of the conveyor belt 28 and this upper length transmits its heat to the moving veneers 11.

Above this heating device 32 a second heating device 33 is arranged which is associated with the proportioning device 13 and is formed as a rectangular body fitted with rotating press rollers 34. These press rollers 34 (see FIGS. 1 and 3) are provided over the entire circumference of the heating device 33 and form a roller chain, the individual press rollers 34 being articulated together by means of connecting straps 36 at the ends of their bearing pins 35. The individual press rollers 34 have helical scores 37 on their rotating pressure surfaces which extends from both ends, with an intermediate unscored portion 38 of the surface to form a herringbone pattern. This unscored strip 38 corresponds approximately to the width of the joint 14. During the travel of the veneers 11, the press rollers 34 resting thereon are set rotating by the veneers 11 and the roller chain formed of the press rollers 34 circulates round the heating device 33. The radiated heat from the heating device 33 is transmitted to the press rollers 34 which then in turn transmit the heat to the veneers 11. At the same time the veneers 11 are drawn together to form a butt joint between them by means of the herringbone scores 37.

The heating device 33 with the press roller chain, is resiliently and vertically adjustably mounted in a frame 39, whereby the press rollers 34 can be adjusted to any thickness of veneer and exert a certain pressure on the moving veneers 11 necessary for the movement of the veneers 11 and to press them together with a butt joint.

The drive of the feeding disc 17 in the proportioning device 13 is connected to the drive of the conveyor belt 28, the peripheral speed of the feeding disc 17 being adjustable to correspond to the thickness of the veener.

The above described apparatus operates as follows:

Veneers 11 which are intended to be glued together along their adjacent longitudinal edges, are pushed on the work table 10 in the direction of the proportioning device 13 and move in contact with the stop ledge 12 and move into the region of the outlet slot 20 of the proportioning device 13 with the gap 14 between them, the width of which is determined by the stop ledge 12.

The powdered glue or adhesive 21 provided in the hopper 22 is kept in a loose condition by means of the loosening device 23 and drops into the individual receiving grooves 18 of the feeding disc 17 which feeds the powdered glue or adhesive 21 in a correctly proportioned dose through the outlet slot 20 into the gap 14. The veneers 11 with powdered glue or adhesive 21 filled into their gap 14 pass into the region of the upper and lower heating devices 32, 33 in their course of travel; these heating devices 32, 33 have heated the conveyor belt 28 and the pressure rollers 34 so that the veneers 11 are subjected to heating in the region of their joint. The conveyor belt 28 moves the veneers 11 through the heating devices 32, 33. During this passage the conveyor belt 28 displaces the veneers 11 in a straight line, whilst the pressure rollers 34 produce an inclined motion by means of their herringbone gear 37, pressing the veneers 11 together. The veneers 11 are thus butt-jointed and the powdered glue or adhesive 21 sets during the passage through the heating devices 32, 33, so that when they leave the heating devices 32, 33 the adjacent veneers 11 are sealed together and firmly connected in the region of their joint.

The apparatus shown in FIGS. 4 and 5 of the drawing for the edge-to-edge glueing of veneers corresponds in its basic construction to the apparatus shown in FIGS. 1 to 3. The different construction of this apparatus resides in the conveyor which in this case is formed of discs arranged below the plane of movement, and upper pressure rollers 41.

In the region of the proportioning device 13 there are two large discs 40 disposed oppositely to each other with which several oppositely disposed discs 40 of smaller diameter are associated arranged in series. These discs 40 receive their movement of rotation in the direction of the joint 14 from a driving mechanism 42 in the region of the work table 10. The bearing shaft 44 of the feeding disc 18 of the proportioning device 13 is connected to the driving mechanism 32 by a belt drive 43 so that a synchronous movement of the conveyor and the proportioning device 13 is achieved. In order to adjust the speed of the feeding disc 17 there is a control disc 48 provided in the region of the driving device 42 for increasing or reducing the speed of the feeding disc 17 relatively to the speed of rotation of the discs 40.

The speed of the feeding disc 17 depends on the thickness of the veneers 11 to be glued, since in the case of comparatively thick veneers, more powdered glue or adhesive must be poured into the gap than in the case of comparatively thin veneers.

The pressure rollers 41 are resiliently and vertically adjustably mounted together in a frame 45 and with their axis of rotation displaced relatively to the axis of rotation of the discs 40. The axis of rotation of the pressure rollers is preferably arranged at a space in front of the axis of rotation of the discs (viewed in the direction of travel of the veneers 11) whereby the displacement and pressing together of the veneers 11 is achieved.

Between the oppositely disposed discs 40 a lower heating device extending 11 together. The veneers 11 are thus butt-jointed and the powdered glue or adhesive 21 sets during the passage through the heating devices 32, 33, so that when they leave the heating devices 32, 33 the adjacent veneers 11 are sealed together and firmly connected in the region of their joint.

The apparatus shown in FIGS. 4 and 5 of the drawing for the edge-to-edge glueing of veneers corresponds in its basic construction to the apparatus shown in FIGS. 1 to 3. The different construction of this apparatus resides in the conveyor which in this case is formed of discs arranged below the plane of movement, and upper pressure rollers 41.

In the region of the proportioning device 13 there are two large discs 40 disposed oppositely to each other with which several oppositely disposed discs 40 of smaller diameter are associated arranged in series. These discs 40 receive their movement of rotation in the direction of the joint 14 from a driving mechanism 42 in the region of the work table 10. The bearing shaft 44 of the feeding disc 18 of the proportioning device 13 is connected to the driving mechanism 32 by a belt drive 43 so that a synchronous movement of the conveyor and the proportioning device 13 is achieved. In order to adjust the speed of the feeding disc 17 there is a control disc 48 provided in the region of the driving device 42 for increasing or reducing the speed of the feeding disc 17 relatively to the speed of retation of the discs 40.

The speed of the feeding disc 17 depends on the thickness of the veneers 11 to be glued, since in the case of comparatively thick veneers, more powdered glue or adhesive must be poured into the gap then in the case of comparatively thin veneers.

The pressure rollers 41 are resiliently and vertically adjustably mounted together in a frame 45 and with their axis of rotation displaced relatively to the axis of rotation of the discs 40. The axis of rotation of the pressure rollers is preferably arranged at a space in front of the axis of rotation of the discs (viewed in the direction of travel of the veneers 11) whereby the displacement and pressing together of the veneers 11 is achieved.

Between the oppositely dispossed discs 40 a lower heating device extending in the region of the joint is disposed terminating at a space from the outlet slot 20 of the proportioning device 13. A heating device 47 arranged in the region of the joint and extending in the direction of movement is disposed between the upper oppositely disposed pressure rollers 41. Both heating devices 46, 47 are directly connected to the moving veneers 11 and transmit their heat to them in the region of the gap 14. The veneers 11, provided in the region of the gap with powdered glue or adhesive 21, pass through the heating devices 46, 47 in which the powdered glue or adhesive 21 is set; at the same time the lower discs 40 press the veneers 11 together to form a sealed joint between them owing to their rotation, whilst the upper pressure rollers 41 provided on both sides of the joint and arranged in a straight line one behind the other, keep the veneers 11 in the plane of movement.

The veneers 11 are glued edge-to-edge when they leave the apparatus and are firmly connected together with a sealed joint between them. The powdered glue or adhesive 21 preferably consists of a thermoplastic synthetic substance which can be used without the addition of a solvent.

The scope of the present invention also includes a lower conveyor belt for displacement in a straight line and upper inclined pressure rollers for pressing the veneers together.

The apparatus of the present invention is characterised by simple construction, reliable operation and speed of movement. It effects an edge-to-edge glueing of veneers which firmly connects them together in a simple and rapid manner.

The proportioning device introducing the powdered glue or adhesive into the joint of adjacent-veneers operates reliably and continuously whilst feeding a constant supply of powder.

The conveyor ensures that the veneers are reliably and efficiently pressed together during the setting of the powdered glue or adhesive so that a neat and close glued butt joint is achieved.

In the case of the apparatus fitted with a conveyor belt, the latter can be kept clean in a simple and rapid manner by a scraper or the like during its circulation. The edgeto-edge glued veneers produced by the apparatus of the present invention have a smooth and clean surface on both sides so that further processing can be applied to either or both sides.

I claims:

1. Apparatus for the edge-to-edge glueing of veneers comprising a table, means for feeding two pieces of veneer parallelly along said table, means for forming and maintaining a gap of predetermined width between said veneers, a proportioning device for periodically introducing a metered quantity of powdered adhesive into said gap, wherein said proportioning device comprises a feeding disc rotating in the region of said gap between the veneers, perpendicularly to the plane of movement and in the direction of movement of said veneers, wherein said feeding disc is provided with receiving grooves for the powdered adhesive, said grooves being distributed over the periphery of said disc, means for pressing said veneer edges together and means for heating said adhesive to set same and bind said veneers together.

2. Apparatus as recited in claim 1, comprising a storage chamber in a housing and a filling aperture and an outlet slot to said chamber, said feeding disc rotating in said storage chamber.

3. Apparatus as recited in claim 2 wherein said receiving grooves of said feeding disc form closed conveyor chambers with the wall of said storage chamber in the region of movement between said filling aperture and said outlet slot.

4. Apparatus as recited in claim 3, comprising a hopper containing the powdered adhesive arranged in the region of said filling aperature of said storage chamber.

5. Apparatus as recited in claim 4, comprising a pinned disc rotating in said hopper to loosen said adhesive, the said pinned disc engaging with slots in said feeding disc.

6. Apparatus as recited in claim 5 wherein said means for forming a gap between said veneers is a stop ledge projecting from said table.

7. Apparatus as recited in claim 5, comprising heating devices provided above and below the plane of movement of said veneers.

8. Apparatus as claimed in claim 5, wherein said means for feeding the veneers is a driven conveyor belt arranged below the plane of movement of the veneers, together with a plurality of scored press rollers disposed in the direction of movement of the veneers, said rollers acting to butt said veneers tightly together, there being links between said rollers.

9. Apparatus as recited in claim 5, wherein said means for feeding said veneers is a plurality of discs between the plane of the veneers pressing said veneers tightly together edgewise together with pressure rollers above the plane of movement of the veneers.

10. Apparatus as recited in claim 5, comprising means for resiliently and adjustably mounting said feeding means, said veneer pressing means and said heater means.

References Cited UNITED STATES PATENTS 1,43 6,023 11/1922 Elmendorf l56544 1,702,185 2/ 1929 Weber l56304 1,870,041 8/1932 Dike 156--283 1,976,055 10/1934 Woodward et al 156-283 1,999,509 4/1935 Merritt 156--238 2,084,676 6/1937 Friz l56546 2,344,488 3/1944 Bowling l56304 2,398,353 4/1946 Bolling 156-446 2,503,551 4/1950 Gustin l56546 2,516,280 7/1950 Welch 156304 5 CARL D. QUA'RFORTH, Primary Examiner G. G. SOLYST, Assistant Examiner US. Cl. X.R. l56283, 546 

